Screw cap

ABSTRACT

We propose a screw closure for containers, particularly bottles, with a top from which extends a surrounding skirt, said screw closure having a holding device for fixing the screw closure to the container, and with a security band disposed at the edge of the skirt that is facing away from the top, said security band being connected to the screw closure via a predetermined breaking line, and at least one elongation zone being provided in the security band, said elongation zone enabling the security band to extend preferably transverse to its circumferential direction. This screw closure is characterized by the fact that the security band ( 11 ) has at least one elastic region ( 39 ) that is formed by the lower part of the security band ( 11 ) between a holding strip ( 29 ) and an elastic holding band ( 35 ).

The invention relates to a screw closure for containers, particularlybottles, according to the preamble of claim 1.

Screw closures of the kind addressed herein are known. They eitherpresent an inner thread that meshes with the outer thread of a containeror they are bayonet locks. In both cases, it is critical that to beopened the screw closure undergo a certain rotatory motion andparticularly an axial transverse motion, whereby the closure is liftedfrom the container or its mouth. It is known to provide such crewclosures with a security band, also known as warranty band, which uponthe first opening, namely when the screw closure is taken off thecontainer for the first time, is deformed or destroyed in certainregions so that the outer contour is changed. As a result of the changedouter contour, a user can immediately recognize that the container is nolonger closed in the original manner and that it possibly has beentampered with. It has been found that the first opening of a screwclosure requires rather high opening forces, to prevent easy opening ofthe closure. Moreover, for many closures of this kind the force neededto reclose the container is relatively high. Finally, in many cases thedeformed security band interferes with reclosure. In the known closures,the warranty band is connected to a predetermined breaking lineextending all around in the circumferential direction and is providedwith a separation line extending vertically thereto. When the closure isopened for the first time, the predetermined breaking line is split insome parts, and the separation line opens up.

The object of the invention is therefore to provide a screw closure ofthe kind addressed herein that does not present these drawbacks.

To reach this objective, we propose a screw closure having the featuresindicated in claim 1. It comprises a top from which extends asurrounding skirt which on its inside is provided with a holding devicefor fixing the screw closure to the container. As mentioned hereinabove,this device can be in the form of a thread or optionally a bayonet lock.As a rule, the screw closure is provided with an internal thread thatcooperates with an outer thread on the container. The screw closure isadditionally fitted with a security band disposed at the edge of theskirt facing away from the top and which is connected to the screwclosure through a predetermined breaking line. The screw closure ischaracterized by the fact that the security band is provided with atleast one elongation zone the extension behavior of which is clearlydifferent from that of the remainder of the security band: The securityband is resilient in the region of the elongation zone, particularlyacross its longitudinal extension, namely across the circumferentialdirection, so that it exhibits higher flexibility. As a result, lessforce is needed for the first opening of the screw closure. The same istrue for the reclosing of the screw closure. During the first opening,the elongation zone is deformed so that the security band does notinterfere when the container is again closed. In this regard, thesecurity band has as a distinguishing feature a closed structure, namelyin the undamaged condition it forms a closed band so that during thefirst closing of the screw closure cannot get interlocked anywhere. Theclosed band is characterized by high stability despite the elongationzone so that during the first closing of a container the security bandremains undamaged with the highest reliability and interference with theclosing procedure is practically eliminated. The elongation zone has thedistinguishing feature that it confers extensibility to the securityband, particularly in the direction perpendicular to the circumferentialdirection of the screw closure, namely perpendicular to the longitudinaldirection of the security band, in other words in the direction of theheight of the security band.

In a preferred embodiment of the screw closure, the elongation zoneextends essentially horizontally. This permits relatively easy and thusinexpensive fabrication of the elongation zone.

Preferred is a screw closure with the distinguishing feature that theelongation zone is displaced relative to the predetermined breaking linein the circumferential direction. As a result of this arrangement, thereis at least one region, referred to as the overlap region, wherein thereis present a predetermined breaking line as well as an elongation zone,said line and said zone being disposed at a distance from each other asseen over the height of the security band. In this manner, an elasticholding band is formed which extends from at the edge of the skirtfacing away from the top and as far as the lower region of the securityband. The elastic holding band stabilizes the security band relative tothe the skirt thus keeping the skirt in a desired position. The forcesneeded for reclosure are thus adjustable, and interference duringreclosure can be avoided.

Also preferred is an embodiment of the screw closure that is providedwith several elongation zones in the region of the security band. Inthis manner, it is possible to influence the elasticity of the securityband in a specific manner so that the opening and reclosing forces canreadily be adjusted to a desired low value.

Particularly preferred is an embodiment of the screw closure wherein acut is provided in the region of the security band, namely an elongationcut that acts as an elongation zone. In the region of the cut, which canbe intermittent and which entirely or partly passes through thethickness of the security band, the security band has higher elasticityor extensibility so that the elongation zone can be fabricated in simplemanner.

In another embodiment of the screw closure, the predetermined breakingline does not extend all the way around. In this manner, it is possibleto obtain a holding region, referred to as a holding strip, that holdsthe security band in the desired position.

Another preferred embodiment of the screw closure has the distinguishingfeature that in the region of the security band, namely between thepredetermined breaking line and the edge of the security band facingaway from top of the screw closure, there is provided at least oneweakening zone preferably extending essentially vertically. It is alsoconceivable for said weakening zone to be disposed at an angle to thevertical direction. It is essential that in the region of the weakeningzone the security band exhibit reduced strength to enable deformationand possibly splitting of the security band to occur in the weakeningzone during the first opening.

Particularly preferred is an embodiment of the screw closure wherein theweakening zone presents weakening regions that are displaced relative toeach other in the circumferential direction. Between the two weakeningregions is a connecting strip the strength of which is determined by thelength of the weakening regions and by the extent of the displacement.In this manner, the strength in the region of the weakening zone can bepredetermined without any particular effort.

Other embodiments of the invention are covered in the remainingsubclaims.

In the following, the invention will be explained in greater detail byway of the drawings in which:

FIG. 1 shows a first embodiment of a screw closure in undamagedcondition;

FIG. 2 is a cross-sectional view along line A-B of FIG. 1;

FIG. 3 is a cross-sectional view along line C-D of FIG. 1;

FIG. 4 shows a screw closure resting on top of a container after thefirst opening;

FIG. 5 depicts a screw closure on a container, the closure showing aspread security band;

FIG. 6 shows a top view of the screw closure of FIG. 1 in the openedcondition;

FIG. 7 shows a side view of a second embodiment of a screw closure inundamaged condition;

FIG. 8 shows a cross-section along line A-B indicated in FIG. 6;

FIG. 9 shows a cross-section of the screw closure shown in FIG. 6 alongline C-D.

The screw closure described in the following has the distinguishingfeature that it is lifted from the container mouth during the firstopening, namely that it undergoes a transverse motion in addition to therotatory one. On the inside of the security band is provided aninterlocking arrangement that cooperates with an abutment on thecontainer that is to be closed. In this manner, a force is applied tothe security band which, on the one hand, acts parallel to thetransverse motion and, on the other, brings about a radial widening ofthe security band.

The first embodiment of a screw closure 1 has a top 3 that spans themouth of the container that is to be closed and from which skirt 5extends all around so that, overall, a cup-shaped screw closure 1, alsoreferred to as a screw cap, is formed. On the outside of skirt 5, therecan be provided, as shown here, ribs extending vertically, namely inparallel with the central or rotation axis 7 of screw closure 1, for thepurpose of increasing the ease of gripping screw closure 1. At edge 9 ofskirt 5 that faces away from top 3 there is provided a security band 11connected to skirt 5 through a predetermined breaking line 13. Said lineis made so that during the first opening security band 11 is detachedfrom skirt 5 in some regions. As a rule, a weakening region is providedor a cut line is made in the wall of the screw closure, namely in theregion between skirt 5 and security band 11, said weakening region orcut line extending through the wall over the entire thickness or only apart of the thickness of security band 11. If the cut extends over theentire thickness of security band 11 then, as a rule, there are providedseveral connectors 15 (see FIGS. 2 and 3) which when the cut is maderemain essentially undamaged and which span predetermined breaking line13. During the first opening, these connectors 15 are torn off so thatthe predetermined breaking line 13 opens up.

The predetermined breaking line 13 can also extend over the entireperiphery of screw closure 1. Preferably, however, it extends over asmaller part of the periphery, for example one amounting to about 240°.Conceivably, it is possible to provide several predetermined breakinglines 13 separated from one another and each extending over a smallerpart of the periphery.

At a distance from edge 9, there is provided beneath predeterminedbreaking line 13 inside security band 11 and approximately parallel topredetermined breaking line 13, an elongation zone 17 in the region ofwhich the extensibility of security band 11 is substantially higher thanin the neighboring region. When—seen in the circumferentialdirection—there are provided several predetermined breaking lines, thenpreferably at least one elongation zone 17 is to be assigned to eachpredetermined breaking line. Elongation zone 17 preferably consists of alinear softer or weakened region of security band 11 and preferably ofan elongation cut. This cut can be a through-cut or an intermittent oneconsisting of individual cut lines. The depth of the cut is selected sothat it extends either only through part of the thickness or through theentire thickens of security band 11, in which case it is necessary toprovide a connecting bridge that spans the cut and is torn during thefirst opening.

Elongation zone 17 has the distinguishing feature that—as seen in thecircumferential direction—it extends at least over a certain partialregion of screw closure 1. When the closure is opened for the firsttime, elongation zone 17 is subjected to a force so that it widensessentially transverse to its long dimension. The elongation zone thusextends essentially transverse to the long dimension or circumferentialdirection of security band 11, namely in the direction of the height ofsecurity band 11 or in the direction of rotation axis 7.

It can be seen from FIG. 1 that in the embodiment presented hereelongation zone 17 extends essentially horizontally and thus practicallyparallel to predetermined breaking line 13 and/or to the edge 19 ofsecurity band 11 facing away from the border. Conceivably, elongationzone 17 can also follow an imagined helical line.

FIG. 1 shows that the screw closure is provided with a weakening zone 21which here comprises a first weakening region 23 disposed betweenpredetermined breaking line 13 and elongation zone 17 and a secondweakening region 25 disposed between elongation zone 17 and edge 19.

Weakening zone 21 has the distinguishing feature that its strength islower than that of the remaining regions of security band 11. Hence,during the first opening, said security band can stretch or preferablybreak in the region of weakening zone 21.

In the embodiment presented here, weakening zone 21 extends essentiallyvertically, namely parallel to rotation axis 7. It can, however, also bemore or less inclined toward said axis. In the embodiment presentedhere, said zone is—as stated—divided into two weakening regions. Theseregions—as seen in the circumferential direction—are somewhat displaced,namely they do not form a weakening region that extends verticallythrough. This is not absolutely necessary. In other words, optionallyonly a single passing-through weakening region may be provided.Weakening zone 21 can thus consist of several vertical weakening regionsor of a single passing-through weakening region. Weakening zone 21 canbe in the form of a linear weakening region, namely a thin-walledregion, or preferably in the form of a weakening cut or weakening cutsconstituting weakening regions 23 and 25. The cuts can pass through theentire thickness of security band 11 or they can pass through only apart thereof. Conceivably, interrupted, intermittent cuts can also beprovided. It is also possible to provide a through-passing cut spannedby a bridge that is torn during the first opening of closure 1.

To reach a defined strength, it is possible, as shown here, to providetwo vertical, displaced weakening regions 23 and 25 between which isretained a connecting strip 27 connecting the upper part of securityband 11 to its lower part. By the distance seen in the circumferentialdirection and by the length of weakening regions 23 and 25 as seen inthe vertical direction, the strength of connecting strip 27 can beestablished in a defined manner and thus also the splittingcharacteristics of security band 11 during the first opening. When inthe region of weakening zone 21 there are provided two mutually aligned,merging weakening regions 23 and 25, the strength in the region ofweakening zone 21 can be established by the depth of the cut or by thethickness of security band 11 or else by an intermittent cut providedwith at least one bridging strip.

The lateral view according to FIG. 1 shows that security band 11 has tworegions between predetermined breaking line 13 and lower edge 19, namelyan upper band region 28 a and a lower band region 28 b. Between theseregions lies elongation zone 17.

FIG. 2 is a cross-sectional view of screw closure 1 of FIG. 1. Identicalparts bear the same reference numerals so that in this respect thereader is referred to the description of FIG. 1.

FIG. 2 shows that predetermined breaking line 13 does not extend allaround but only around a region of about 240°. In a peripheral region ofabout 120°, edge 9 of screw closure 1 is not weakened or cut. In otherwords, here there is no predetermined breaking line 13, either. Here, inthis region, skirt 5 is firmly connected to security band 11, namely tothe upper band region 28 a thereof.

The cross-sectional view according to FIG. 3 shows that elongation zone17 also does not extend all the way around. In the embodiment presentedhere, said zone extends over a circumferential angle of about 125°. Tothe left of elongation zone 17, a holding strip 29 is formed by the factthat here security band 11 has no predetermined breaking line 13 and noelongation zone 17. In other words, here security band 11 is fasteneddirectly to edge 9 of skirt 5 of screw closure 1 or forms a single unitwith it. Holding strip 29 preferably extends over a region of about 12°to 18° and particularly 15°.

Holding strip 29 extends as far as the lower band region 28 a so thathere this region is connected with skirt 5.

On the other side of elongation zone 17 that faces away from holdingstrip 29 there is located an overlap region 31 wherein there exists, onthe one hand, predetermined breaking line 13 and, on the other,elongation zone 17 located at a distance therefrom—as seen in thedirection of rotation axis 7. In this case, predetermined breaking line13 and elongation zone 17 are disposed from one another at a distancethat corresponds to the height of upper band region 28 a.

The undamaged regions of screw closure 1 that forms holding strip 29 andoverlap region 31 can be established in terms of their width, asmeasured in the circumferential direction, by appropriate selection ofthe circumferential length of predetermined breaking line 13 andelongation zone 17. The overlap extends over a region of 30° to 36° andpreferably about 33° or, in other words, over a region amounting to{fraction (1/10)} to ½ of the circumference.

The weakening zone 21 and particularly the second weakening region 25can be seen in FIGS. 2 and 3.

FIG. 4 shows screw closure 1 on a container, here on a bottle 33. It isevident that screw closure 1 has been opened for the first time. Partscoinciding with those shown in preceding figures are indicated by thesame reference numerals. In this respect, the reader is referred to thedescription of FIGS. 1 to 3.

During the first opening of screw closure 1, security band 11 was tornin the region of weakening zone 21, namely in the first weakening region23 and in the second weakening region 25 as well as in the region ofpredetermined breaking line 13 and elongation zone 17. In the region ofpredetermined breaking line 13, security band 11 is completely detachedfrom skirt 5. It is connected to edge 9 of skirt 5 only where there isno predetermined breaking line 13, for example in the region of holdingstrip 29. Elongation zone 17 is slightly spread, because security band11 was deformed during the first opening. To the left of elongation zone17 can be seen holding strip 29 wherein the lower part of security band11, referred to as lower band region 28 b namely the region locatedbelow elongation zone 17, is connected with the upper part of securityband 11, referred to as the upper band region 28 a, and with it to edge9 of screw closure 1. In the region of the right edge of elongation zone17 formed by overlap region 31 (see FIG. 3) there is provided an elasticholding band 35 which elastically connects the lower band region 28 b ofsecurity band 11 with the upper band region 28 a of security band 11 andfinally with skirt 5.

Elastic holding band 35 holds the split segment in the region ofelongation zone 17 and the segment broken in the region of thepredetermined breaking line 13 of security band 11 in a desired spreadposition so that the forces required for reclosure are minimized andsecurity band 11 is held so that it does not interfere when thecontainer or bottle 33 is reclosed with screw closure 1.

The following is quite evident. The width of holding strip 29, as seenin the circumferential direction, is defined by the distance of the leftend of elongation zone 17 to weakening zone 21. The size of overlapregion 31 as measured in the circumferential direction defines thelength of the elastic holding band 35, and the distance betweenelongation zone 17 and predetermined breaking line 13 as measured in thevertical direction determines the height and thus the strength ofelastic holding band 35 and, hence, also the elasticity of security band11.

In other words, the strength of holding strip 29 and that of elasticholding band 35 can thus be established in simple manner, the selectionof the material constituting security band 11, of course, also playingan essential role in this regard.

FIG. 5 shows once again screw closure 1 placed on a bottle 33. Heresecurity band 11 is bent approximately linearly against its inherentelasticity. In other words, it no longer extends along a bent contouraround container 33. This arrangement of security band 11 is not the onewhich said band assumes in a regular functional position, but servesonly to explain the configuration of screw closure 1. Identical partsare indicated by the same reference numerals so that for a descriptionthe reader is referred to the preceding figures.

Security band 11 is thus provided with two band regions. An upper bandregion 28 a follows directly predetermined breaking line 13. A lowerband region 28 b reaches as far as edge 19 of security band 11. To theright of elongation zone 17, the upper and lower region of security band11 are connected to each other or form a single unit. In other words,here there are no weakening or elongation zones.

At the right, free end of security band 11 can be seen weakening zone 21which extends around the upper, first weakening region 23 in upper bandregion 28 a and the lower, second weakening region 25 displaced incircumferential direction in the lower band region 28 b. Both weakeningregions 23 and 25 are split when screw closure 1 is opened for the firsttime so that here a step is almost formed. Weakening zone 21 as a rulesplits already during the first opening of screw closure, and at thelatest when screw closure 1 is lifted from the container mouth.

It is evident from FIGS. 1 to 5 that the outer surface of upper bandregion 28 a of security band 11 as applied widens in slightly conicalmanner starting at skirt 5 and that lower band region 28 b of securityband 11 has a cylindrical shape. It is quite conceivable that theconical widening also extends over the lower band region 28 b ofsecurity band 11 or that the upper band region 28 a of security band 11can have an essentially cylindrical shape.

The total height of security band 11 determines its strength. The heightof upper band region 28 a amounts to about one third of the total heightand in particular from 0.3 to 0.33 times the total height. For a totalheight of security band 11 of about 4.2 mm, the height of upper bandregion 28 a is then about 1.26 mm to about 1.4 mm. The connection ofsecurity band 11 to skirt 5 of screw closure 1 or to its edge 9 occursvia elastic holding band 35 and also via holding strip 29. Theseconnections also predetermine the breaking properties of security band11 overall and in the region of elongation zone 17 during the firstopening of screw closure 1. These properties also depend on the materialconstituting screw closure 1.

It is important that elongation zone 17 and weakening zone 21 reduce theoverall strength and increase the elasticity of security band 11 so thatless strength is needed to open screw closure 1 for the first time. Theelasticity of security band 11 can be influenced by the length ofelongation zone 17. Moreover, the free-standing region of security band11 is kept in spread position by elastic holding band 25 so that a firstopening and thus tampering can be reliably recognized, the reclosingforces can be reduced and security band 11 does not interfere withreclosure.

FIG. 6 is a top view of screw closure 1 as explained with the aid ofFIGS. 1 to 5. Identical parts are indicated by the same referencenumerals so that for a description the reader is referred to thepreceding figures.

Screw closure 1 has already been opened so that, as shown in FIG. 4,security band 11 is radially split. This readily indicates to the userthat tampering with and a first opening of screw closure 1 had takenplace.

It is evident that security band 11 is spread to an extent such that itno longer interferes with the reclosure of the container. Free end 37can support itself on the lower edge 9 of skirt 5 and is thus heldreliably in the spread position. Moreover, security band 11 is keptreliably in the spread position by elastic region 39 formed by lowerband region 28 b of security band 11 between holding strip 29 andelastic holding band 35 so that already for this reason said securityband does not interfere with reclosure, and the forces required forreclosure are clearly reduced. The elasticity of the fixed, elasticregion 39 is determined by the length of elongation zone 17 and/or theaxial distance of elongation zone 17 from edge 9 of security band 11.

The reason why security band 11 is held very well in the spread positionby elastic region 39 is that at one of its ends elastic region 39 issupported at holding strip 29, namely it is also connected directly withskirt 5 of screw closure 1.

The purpose of elastic holding band 35 is, on the one hand, also to holdsecurity band 11 in a more or less spread position, as can be seen fromFIG. 6. On the other hand, however, it also serves to maintain thespreading in the region of elongation zone 17 that occurred during thefirst opening, as can be seen from FIG. 4. In this case, as shown inFIG. 4, the lower band segment 28 b of security band 11, namely elasticregion 39, is kept at a distance from its upper band region 28 a so thatby this axial spreading, too, tampering with and a first opening ofscrew closure 1 can readily be recognized by a user.

Unlike in FIG. 6, security band 11 can with its free end 37 also lieslightly inside the outer boundary line of screw closure 1. It isessential that said band be held over its entire length at a radialdistance from skirt 5 of screw closure 1 so that the interlocking andfastening devices, not shown here, disposed on the inside of securityband 1 and which can have the form of barbs do not interfere withreclosure of the container and the reclosing forces are therebysubstantially reduced. The fastening devices can be oriented anddisposed relative to predetermined breaking line 13 and particularlyrelative to elongation zone 13 so that security band 1 is stabilizedduring the first attachment of screw closure 1 and during transport ofthe closed container.

It can thus be seen from FIG. 6 that elastic region 39 is held at aradial distance from skirt 5. The distance of the remaining securityband 11 can be increased further in the radial direction by thespreading forces of elastic region 39 and by the holding forces ofelastic holding band 35. We found that the barbs provided on the insideof security band 11 are in their original position only in the region ofholding strip 29. The barbs on the inside of elastic region 39 and onthe inside of the remaining security band 11 are displaced radiallyoutward. As a result, as already stated, during closing, namely whilethe closure is being screwed on, the barbs of screw closure 1 cannotinterfere and the reclosure forces are clearly reduced.

FIG. 7 shows a modified embodiment 1′ of the screw closure, similar tothe one explained by way of FIGS. 1 to 6. Identical parts are indicatedby the same reference numerals so that for a description the reader isreferred to the preceding figures.

Screw closure 1′ also has a top 3 from which extends skirt 5. On edge 9of said skirt, facing away from top 3, is attached a security band 11which via a predetermined breaking line 13 is connected to edge 9 andhas an elongation zone 17. In the embodiment of screw closure 1′presented here, as in the embodiment presented hereinabove,predetermined breaking line 13 does not have to extend all the wayaround and—and this also applies to the above-describedembodiment—several individual segments of a predetermined breaking linecan be provided. The same is also true for elongation zone 17 in bothembodiments. In other words, in both embodiments there can be providedone or more elongation zones 17 as will be explained in greater detailby reference to FIGS. 8 and 9.

The essential difference of the embodiment of screw closure 1′ presentedin FIGS. 7 to 9 is that it does not have a weakening zone which in theafore-described embodiment is identified by reference numeral 21.

In the embodiment presented here, predetermined breaking line 13 extendsessentially horizontally, as does elongation zone 17. For thisembodiment, as for the afore-described one, however, the predeterminedbreaking line and the elongation zone can extend at an angle inclinedtoward the horizontal or they can follow an imagined helical line. It isessential that predetermined breaking line 13 and elongation zone 17intersect in a region Ü, namely that an overlap region 31 is formed, aswas already explained by way of FIG. 3. The length of the intersectionin region Ü, indicated by a double-headed arrow, can be selected withina wide range as can the axial distance, as measured in the direction ofrotation axis 7, between predetermined breaking line 13 and elongationzone 17. As a result of this configuration, here, too, an elastic band35 is formed which after the first opening of screw closure 1′ connectsan upper band region 28 a of security band 11 with the lower band region28 b and which after the first opening holds the lower band region 28 bof security band 11 in a spread position as can be seen in FIG. 4. Lowerband region 28 b of security band 11 is thus radially spread anddisposed at a distance from the upper band region. Moreover, elongationzone 17 is kept in the spread condition so that tampering and a firstopening are readily recognizable.

A second elongation zone 17 a can be seen at the left end ofpredetermined breaking line 13 presented in FIG. 7. In principle, firstelongation zone 17 could extend around a length which would makeelongation zone 17 a its second end, namely the end of elongation zone17 facing away from overlap region 31. Here, however, it has beenassumed—as can be seen in FIG. 9—that two elongation zones 17 and 17 aare present. The right-hand end of elongation zone 17 a does notintersect the left-hand end of predetermined breaking line 13 so thathere the lower band region 28 b of security band 11 is connected, viaits upper band region 28 a, with edge 9 of skirt 5 of screw closure 1′thereby forming holding strip 29. By means of holding strip 29, thelower band region 28 b can, as described hereinabove, be supportedreliably on skirt 5 so that the desired spreading forces are ensured.

Screw closure 1′ is similarly configured on the opposite side, namely onthe side hidden in FIG. 7. This means that elongation zone 17 a has aregion 31 where it overlaps with a second predetermined breaking line,not shown, so that here, too, an elastic holding band 35 a is formed. Inother words, there can be provided several elongation zones disposed ata distance from each other in the circumferential direction. Here, as inthe first embodiment, it is possible to provide several elongation zonesdistributed over the height of security band 11.

FIG. 8 is a cross-sectional view of screw closure 1′ along line A-B ofFIG. 7. It can be seen here that the predetermined breaking line 13shown in FIG. 7 extends in this case over a circumferential region of,for example, about 100°. On the opposite side there is provided acentrosymmetric predetermined breaking line 13 a.

At one end, here the right end, of predetermined breaking line 13, 13 athere is provided overlap region 31, 31 a which in this case extendsover a region of, for example, about 30°. It is shown in FIG. 8 thatover a region of about 10° there is no intersection betweenpredetermined breaking line 13, 13 a and elongation zone 17, 17 a sothat holding strip 29, 29 a is formed.

FIG. 9 shows a cross-section of screw closure 1′ along line C-D of FIG.7. Here it can be seen that elongation zones 17 and 17 a extend over acircumferential region of about 100° and that they are disposedsymmetrically relative to one another.

Overall, the following is obvious. In both embodiments of screw closures1, 1′, security band 11, which via a predetermined breaking line 13 isconnected to edge 9 of skirt 5, is provided with at least one elongationzone 17. Predetermined breaking line 13, which does not extend all theway around, in some regions intersects elongation zone 17 which, too,does not extend all the way around, so that there is provided at leastone overlap region 31. Through elongation zone 17, security band 11 inthis fixed, namely radially not freely spread region, is provided withan elasticity that facilitates the reclosure of a container. In overlapregion 31 is formed an elastic holding band 35 that holds security band11 after the first opening of screw closure 1, 1′. On the one hand, bymeans of elastic holding band 35, in the region of elongation zone 17, alower elastic region 39 of security band 11 facing away from skirt 5 iskept in spread position at an axial distance from the upper region ofsecurity band 11. On the other hand, elastic holding band 35 can hold asecurity band 11 spread in the circumferential direction at a radialdistance from skirt 5.

Security band 11 is spread particularly when a weakening zone 21 isprovided, as explained for the embodiment presented by way of FIGS. 1 to6. But even without such a weakening zone, as explained for theembodiment presented in FIGS. 7 to 9, and without the spreading ofsecurity band 11, elongation zone 17 in security band 11 provides areliable indication of tampering with and first opening of screw closure1. Moreover, in all embodiments, security band 11 is weakened byelongation zone 17 so that the additional extension reduces the forcesrequired for a first opening as well as those required for reclosure.

Beneath elongation zone 17 of both screw closures 1 and 1′, in the lowerband region 28 b, there is formed elastic region 39 which not only isspread axially but also radially, as explained in greater detail byreference to FIG. 6. By this radial spreading, in both embodiments thebarbs located on the inner surface of elastic region 39 are alsodisplaced radially outward so that they cannot interfere with thereclosure of a container. At the least, the forces for reclosure aremuch reduced.

It can also be seen from FIG. 4 that the lower band region 28 b locatedbelow elongation zone 17, namely, in particular, elastic region 39 isswiveled downward. By the connection of elastic region 39 to holdingstrip 29, on the one hand, and to elastic band 35, on the other, atilting motion results whereby the barbs located on the inner surface ofelastic region 39 are also swiveled. Also as a result of this swiveling,the barbs do not interfere with the reclosure of a container, and atleast the forces required for reclosure are reduced.

The basic principle of the additional elongation zone described here, asexplained by way of FIGS. 1 to 6, is realized with a single elongationzone 17. It is also possible, however, to provide several elongationzones as seen in the circumferential direction and over the height ofsecurity band 11, as explained by reference to FIGS. 7 to 9, and whichalso applies to screw closure 1. When several elongation zones 17 areprovided over the height of security band 11, then overlap regions canbe provided between them so that, correspondingly, several elasticholding bands also are formed. It is also possible that at one or moreelongation zones at both ends there are overlaps with the predeterminedbreaking line and/or the elongation zones so that elastic holding bandsare formed on both sides. Such an arrangement provides especially highextensibility of security band 11 in the direction of the rotating axisof screw closure 1, namely over the height of security band 11. Here,the aforedescribed support of an elastic region 39 is, of course, not asstrong. In other words, in this case the spreading can be reduced if theholding strips are not reinforced. The horizontal regional support ofsecurity band 11 by one or, in particular, several elongation zones, canbring about increased extensibility in radial and circumferentialdirection whereby the first opening and the reclosure are additionallyfacilitated.

The advantages of screw closure 1 and 1′ described here ariseparticularly when a weakening zone 21 is provided which extendsessentially transverse to the extension of security band 1, namely inthe vertical direction. In this case, one or more weakening regions canbe provided. In the embodiment of FIGS. 1 to 6, two weakening regions 23and 25 have been explained. The splitting of security band 11 in theregion of weakening zone 21 causes an additional splitting in radialdirection which makes it very easy to recognize a first opening andtampering. It is evident from embodiment 1′, however, that weakeningzone 21 optionally can also be omitted without losing the advantages ofthe additional elongation zone. Tampering and first opening are reliablyindicated also by the axial deformation or widening of security band 11alone. The reliability of such indication is further increased by thefact that a radial widening takes place

Expansion zone 17 and optionally 17 a can be formed in any desiredmanner. Conceivable is a linear weakening of the material. Inparticular, however, an elongation cut in security band 11 is provided.The same is true for predetermined breaking line 13 which can be made inscrew closure 1, 1′, but preferably consists of a cut line. In both thecase of predetermined breaking line 13 and elongation zone 17 or 17 a,the cut can penetrate through the entire thickness of security band 11or only through part of it. Conceivably, intermittent cuts, namelysuccessive cut lines, can be made to provide the predetermined breakingline or elongation zone.

The same is true for the weakening zone 21 which can have one or moreweakening regions. Note also that unlike in the embodiment explained byreference to FIGS. 1 to 6, there can be provided several such weakeningzones 21. The segments of the split security band 1 formed during thefirst opening are then formed in a manner similar to the security bandthat was explained by reference to FIGS. 1 to 6. Hence, the number ofelongation zones must be adapted to the number of weakening zones inorder to be able to form at least one holding strip and at least oneelastic holding band for each security band region.

From all this, it is evident that holding strip 29 which cooperates withelastic region 39, is of critical importance for the advantagesdescribed here. Via holding strip 29, elastic region 39 can be supporteddirectly on skirt 5 of screw closure 1 so that, on the one hand, elasticregion 39 is held in its axially as well as radially spread position. Onthe other hand, by elastic region 39 being supported on holding strip29, it can be ensured that the remaining region of security band 11 willbe held in a spread position. In this manner, as described, the barbs onthe inside of security band 11 are kept at a distance such that theforces needed to reclose a container are greatly reduced.

The function of holding strip 29 can also be seen in connection withweakening zone 21: Holding strip 29 holds security band 11 attached toskirt 5 in the region of weakening zone 21 so that during the firstopening of screw closure 1 weakening zone 21 is reliably split orweakened to the extent that it will break the first time screw closure 1is removed. The strength of holding strip 29 is ensured by the fact thaton the side facing weakening zone 21 of holding strip 29, the horizontalpredetermined breaking line 13 that spans weakening zone 21 extends intoholding strip 29 only in a very small region. Preferably, care is takenthat predetermined breaking line 13 extends into holding strip 29 onlyjust a little so that the region of holding strip 19 weakened bypredetermined breaking line 13 amounts to a maximum of {fraction (1/60)}of the circumference of screw closure 1. If predetermined breaking line13 penetrates further into holding strip 29, then during the firstopening of screw closure 1, the region of holding strip 29 facingweakening zone 21 could be bent away downward so that weakening zone 21would not split reliably. For this reason, the region weakened bypredetermined breaking line 13 in the region of holding strip 29 islimited to the above-indicated value.

On the other side of holding strip 29, namely on the side facing awayfrom weakening zone 21, elongation zone 17 penetrates slightly intoholding strip 29. In other words, said strip is weakened, on the onehand, by a small region of predetermined breaking line 13 and, on theother, by a region of elongation zone 17 extending into holding strip29. It is necessary to ensure that in the region of holding strip 29 thepredetermined breaking line 13 and elongation zone 17 are disposed atsuch a distance from one another that during the first opening holdingstrip 29 does not break. The distance from the first weakening region 23of weakening zone 21 to elongation zone 17 amounts to {fraction (1/20)}to {fraction (1/30)} of the circumference of screw closure 1, asmeasured in the circumferential direction. By the afore-indicatedminimal residual width of holding strip 29, it is also ensured thatholding strip 29 can provide sufficient holding forces for elasticregion 39.

Preferably, screw closure 1, 1′ is made of a plastic material andparticularly by the compression molding or injection molding process.This embodiment has the distinguishing feature that the screw closurethen consists entirely of a plastic material. It is also possible,however, to combine a security band 11 made of plastic material with ascrew closure the top and skirt of which consist of a deep-drawablematerial, particularly of metal. Aluminum has been found particularlywell suited for screw closures of the kind discussed here. The securityband can be connected in the known manner with the edge of the skirtfacing away from the top and can be configured as explained withreference to FIGS. 1 to 9. In an embodiment of this kind, too, it ispossible to realize the advantages described herein even if securityband 11 consists of a plastic material.

Screw closure 1, 1′ described herein is suitable for disposable as wellas reusable containers of all kinds made of glass, PET and the like, andparticularly for bottles.

1. Screw closure for containers, particularly bottles, with a top fromwhich extends a surrounding skirt, said screw closure being providedwith a holding device for fixing the screw closure to the container, andwith a security band positioned on the edge of the skirt facing awayfrom the top and which is connected to the screw closure via apredetermined breaking line, said security band being provided with atleast one elongation zone preferably enabling the security band toextend across its circumferential direction, characterized in that thesecurity band (11) has at least one elastic region (39) that is formedby the lower part of the security band (11) between a holding strip (29)and an elastic band (35).
 2. Screw closure according to claim 1,characterized in that the elongation zone (17; 17 a) extends essentiallyhorizontally.
 3. Screw closure according to claim 1 or 2, characterizedin that the elongation zone (17; 17 a) extends essentially parallel tothe predetermined breaking line (13) and/or to the edge (19) of thesecurity band (11) that is facing away from the top (3) of the screwclosure (1; 1′).
 4. Screw closure according to one of the precedingclaims, characterized in that the elongation zone (17; 17 a) extendsalong an imagined helical line.
 5. Screw closure according to one of thepreceding claims, characterized in that at least one elongation zone(17; 17 a) is displaced in the circumferential direction relative to thepredetermined breaking line (13; 13 a).
 6. Screw closure according toone of the preceding claims, characterized in that there are providedseveral elongation zones (17; 17 a).
 7. Screw closure according to oneof the preceding claims, characterized in that the predeterminedbreaking line (13; 13 a) and/or the elongation zone (17; 17 a) aredisposed at a distance from each other—as seen in the circumferentialdirection and/or or in the direction of the height of the security band(11).
 8. Screw closure according to one of the preceding claims,characterized in that there are provided several elongation zonesdistributed over the height of the security band (11) and whichpreferably overlap each other.
 9. Screw closure according to one of thepreceding claims, characterized in that at least one elongation zone(17; 17 a) is essentially linear.
 10. Screw closure according to one ofthe preceding claims, characterized in that between the predeterminedbreaking line (13) and at least one elongation zone (17) and/or betweenseveral elongation zones (17) that are displaced in the direction of theheight there is provided in each case at least one overlap region (31)and that in each case there is formed at least one elastic holding band(35).
 11. Screw closure according to one of the preceding claims,characterized in that at least one elongation zone (17; 17 a) isconfigured as an elongation cut.
 12. Screw closure according to one ofthe preceding claims, characterized in that the security band (11) isconnected directly to the edge (9) of the skirt (5), preferably in aholding region realizable by a holding strip (29).
 13. Screw closureaccording to one of the preceding claims, characterized in that thepredetermined breaking line (13) is realizable via a weakening zoneand/or a cut line.
 14. Screw closure according to one of the precedingclaims, characterized in that in the region between the predeterminedbreaking line (13) and the edge (19) of the security band (11) that isfacing away from the top (3) of the screw closure (1; 1′) there isprovided at least one, preferably vertically extending, weakening zone(21).
 15. Screw closure according to one of the preceding claims,characterized in that the weakening zone (21) has a first weakeningregion (23) extending between the predetermined breaking line (13) andthe elongation zone (17; 17 a).
 16. Screw closure according to one ofthe preceding claims, characterized in that the weakening zone (21) hasa second weakening region (25) extending between the elongation zone(17; 17 a) and the edge (19) of the security band (11).
 17. Screwclosure according to one of the preceding claims, characterized in thatthe first and the second weakening region (23, 25) merge into oneanother.
 18. Screw closure according to one of claims 1 to 16,characterized in that the first and the second weakening region (23, 25)are displaced relative to each other as seen in the circumferentialdirection.
 19. Screw closure according to one of the preceding claims,characterized in that the weakening zone (21) is configuredintermittently.
 20. Screw closure according to one of the precedingclaims, characterized in that the weakening zone (21) is disposed at adistance from an elongation zone (17).
 21. Screw closure according toone of the preceding claims, characterized in that a holding strip (29)is disposed between the weakening zone (21) and the elongation zone(17).
 22. Screw closure according to one of the preceding claims,characterized in that the security band (11) has an upper band region(28 a) and a lower band region (28 b).
 23. Screw closure according toone of the preceding claims, characterized in that the holding strip(29) connects the upper band region (28 a) and preferably also the lowerband region (28 b) to the skirt (5).
 24. Screw closure according to oneof the preceding claims, characterized in that the elastic region (39)is supported by the skirt (5) via holding strip (29).
 25. Screw closureaccording to one of the preceding claims, characterized in that in theregion between the weakening zone (21) and the elongation zone (17) thesecurity band (11) is connected directly to the skirt (5), preferablyvia a holding strip (29).
 26. Screw closure according to one of thepreceding claims, characterized in that the weakening zone (21) isessentially linear.
 27. Screw closure according to one of the precedingclaims, characterized in that the weakening zone (21) is provided with aweakening cut.
 28. Screw closure according to one of the precedingclaims, characterized in that the weakening cut passes through thethickness of the security band (11).
 29. Screw closure according to oneof the preceding claims, characterized in that the weakening cut passesthrough a part of the thickness of the security band (11).
 30. Screwclosure according to one of the preceding claims, characterized in thatan interlocking device is provided on the inside of the security band(11).
 31. Screw closure according to one of the preceding claims,characterized in that the interlocking device has at least one barb. 32.Screw closure according to one of the preceding claims, characterized inthat the predetermined breaking line (13) and/or the elongation zone(17; 17 a) are disposed in the region of the interlocking device. 33.Screw closure according to one of the preceding claims, characterized inthat the security band (11) is made of a plastic material.
 34. Screwclosure according to one of the preceding claims, characterized in thatsaid closure is made of a plastic material and/or a metal, preferablyaluminum.
 35. Screw closure according to one of the preceding claims,characterized in that the screw closure (1; 1′) and/or the security band(11) can be made by the compression molding or injection moldingprocess.